Gluing the back of the chest was an exercise in playing Jenga(tm). While the glued joints seem sturdy enough, that thing was sagging like mad once I put the books on it. Not wanting to risk my Transformer turning into a home improvement project gone wrong, I stacked a bunch of cans of spray paint et cetera to support the middle.
When all was said and done, I ended up with a box that tapered off at the bottom. The fit isn't bad, it leaves about an inch of space on both the front and back. Arm holes still need to be cut out but I can do that in a little bit. (In other words, when I'm feeling more patient.) I don't want an Optimus Prime costume with arms sticking out of his hips. Or do I... (No.)
Given the amazing (read: craptastic) job I did of aligning and cutting the layers for Optimus Prime's windows, I needed to add a few spacers and do some trimming here and there. You can see the vertical wedges to even things out in between the window frame halves. I'm not incredibly concerned about how things will look inside as most of the time the windows will be closed.
In gluing the windows, I had to invoke all the skill I got from playing Jenga again. (Seriously, it's on my resume right under my ability to set up that damned thing from Mouse Trap in under 18 hours.) You can see how much the front is sagging, and that's 1 inch thick styrofoam. It looks like a geriatric transformer.
Here is the chest, now dry. As with everything on this costume, I'll have to trim the pieces here and there to ensure they line up well.
With that done, I painted the windows. Why not. I'm going to hold off on painting the torso until I can get the 'box' on the back. Yeah. Optimus Prime has a little box on his back. I also think I'm going to get the top of the torso done too and maybe the hip-piece. I don't know if I need to make it shorter yet. We'll see.